HR: 10:50h
AN: C22A-03    [Abstracts]
TI: A Younger and Thinner Multiyear Ice Pack: Significance for Extreme, Accelerated and Sustained Losses of Arctic Sea Ice Cover
AU: * Maslanik, J A
EM: james.maslanik@colorado.edu
AF: University of Colorado, Colorado Center for Astrodynamics Research, University of Colorado, CCAR, 431UCB, Engr. Center, North Tower, Boulder, CO 80309, United States
AU: Fowler, C
EM: cfowler@colorado.edu
AF: University of Colorado, Colorado Center for Astrodynamics Research, University of Colorado, CCAR, 431UCB, Engr. Center, North Tower, Boulder, CO 80309, United States
AU: Stroeve, J
EM: stroeve@kryos.colorado.edu
AF: University of Colorado, Cooperative Institute for Research in Environmental Sciences, University of Colorado, CIRES, 449UCB, Boulder, CO 80309, United States
AU: Drobot, S
EM: sheldon.drobot@colorado.edu
AF: University of Colorado, Colorado Center for Astrodynamics Research, University of Colorado, CCAR, 431UCB, Engr. Center, North Tower, Boulder, CO 80309, United States
AU: Zwally, H J
EM: zwally@icesat2.gsfc.nasa.gov
AF: National Aeronautics and Space Administration, Laboratory for Hydrospheric Processes, NASA/Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771, United States
AU: Yi, D
EM: donghui@icesat2.gsfc.nasa.gov
AF: National Aeronautics and Space Administration, Laboratory for Hydrospheric Processes, NASA/Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771, United States
AB: A satellite-derived record of sea-ice is combined with ice thickness estimates from the ICESat satellite to investigate the role of large-scale ice transport in modifying the distribution of ice age and thickness within the Arctic Ocean. These data show that in addition to the well-documented loss of the perennial ice cover over the last several years, the amount of the oldest and thickest ice within the remaining multiyear ice pack has declined significantly, and is now found over a much smaller area of the Arctic Basin. Ice greater than 5 years old covers 56 percent less of the Arctic Ocean than in the early 1980s, and the majority of the remaining perennial pack now consists of ice 2 to 3 years old. Locations of thinning due to this transition to younger ice have shifted from the Siberian Arctic to the western Arctic Basin, consistent with large-scale ice transport patterns. Multiyear ice is no longer surviving the typical east-to-west transit through the Canada Basin. As a result, the clockwise circulation of the Beaufort Gyre, rather than allowing ice to age and thicken for several years within the Arctic Basin as in the past, is now contributing to the loss of the oldest ice. The resulting younger and thinner ice pack is predisposed toward rapid, extensive and persistent reductions in ice extent. This is consistent with the extreme retreat of the ice pack underway this summer that is unprecedented over the available record of sea ice data, with August ice extent 15 percent below the previous observed minimum.
DE: 0750 Sea ice (4540)
DE: 0762 Mass balance (1218, 1223)
DE: 0774 Dynamics
DE: 0798 Modeling
DE: 1621 Cryospheric change (0776)
SC: Cryosphere [C]
MN: 2007 Fall Meeting